ERA10CA001

NTSB accident investigation · Bell 47D1 · Dorrance, PA · October 2, 2009

Accident · No injuriesData collectionFinal report
Date
October 2, 2009, 10:25 local (14:25 UTC)
Place
Dorrance, PA
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N74004Bell 47D1
Defining event
Enroute-descent: Fuel exhaustion
Weather
Visual (VMC) · Day
Status
Completed · report March 3, 2010
Report
Approved by Office Director
NTSB office
Eastern Region Aviation
Parties
FAA/FSDO
FAA report
20091002049919A
Case key
74840

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

A total loss of engine power due to fuel exhaustion for undetermined reasons.

Findings · 2

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Fluids: fuelAircraft › Fluids/misc hardware · Fluid levelBell 47D1: 2 casesAll aircraft: 1,695 casesProbable cause
Not determinedNot determined › Not determined · Unknown/Not determinedBell 47D1: 4 casesAll aircraft: 2,247 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

The pilot reported that he performed a preflight inspection of his helicopter "including checking fuel tank was full and without water or other contaminants." The cross country flight was estimated to be one hour and forty-five minutes. Based upon past performance and lack of guidance from the manufacturer, he determined that the helicopter consumed about 13 gallons-per-hour, resulting in a total consumption of 22.8 gallons of fuel, which would leave approximately 6 gallons remaining in the 29-gallon fuel system. After one hour and twenty five minutes of flight time and approximately 5 nautical miles from the destination airport, the engine quit suddenly. The pilot performed an autorotation maneuver; however, the tail boom impacted a dirt and stone pile causing substantial damage to the tail boom. Post accident examination by a Federal Aviation Administration inspector revealed that "the fuel tank was empty" and a "small amount of fuel was found in both the carburetor and the gascolator." Samples from both were verified to be free of water or contaminants. A slight indication of blue fuel stain was found at the fitting for the fuel line which connects the fuel tank and the carburetor. Additional inspection and testing was performed by the helicopter’s Airframe and Powerplant maintenance technician twelve days after the accident in an effort to determine the origin of the fuel leak; however, the results were inconclusive. Fuel stains were noted on the carburetor around the split line of the two body halves, and around the fuel strainer screen on the left side.

Factual narrative

The pilot reported that he performed a preflight inspection of his helicopter "including checking fuel tank was full and without water or other contaminants." The cross country flight was estimated to be one hour and forty-five minutes. Based upon past performance and lack of guidance from the manufacturer, he determined that the helicopter consumed about 13 gallons-per-hour, resulting in a total consumption of 22.8 gallons of fuel, which would leave approximately 6 gallons remaining in the 29-gallon fuel system. After one hour and twenty five minutes of flight time and approximately 5 nautical miles from the destination airport, the engine quit suddenly. The pilot performed an autorotation maneuver; however, the tail boom impacted a dirt and stone pile causing substantial damage to the tail boom. Post accident examination by a Federal Aviation Administration inspector revealed that "the fuel tank was empty" and a "small amount of fuel was found in both the carburetor and the gascolator." Samples from both were verified to be free of water or contaminants. A slight indication of blue fuel stain was found at the fitting for the fuel line which connects the fuel tank and the carburetor. Additional inspection and testing was performed by the helicopter’s Airframe and Powerplant maintenance technician twelve days after the accident in an effort to determine the origin of the fuel leak; however, the results were inconclusive. Fuel stains were noted on the carburetor around the split line of the two body halves, and around the fuel strainer screen on the left side.

Aircraft

Registration
N74004
Reported as
Bell 47D1
Category
Helicopter
Serial number
403
Airframe hours
9,389
Engine
Franklin 6V4 SERIES, 210 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Operator
House Guy C
Registered owner
House Guy C
Airworthiness certificate
Standard, Normal
Last inspection
Annual · June 9, 2009
Departed
Castle Creek, NY
Destination
KHZL · Hazelton, PA

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
54
Injuries
None
Certificate
Commercial
Medical
Class 3, Without waivers/limitations
Last flight review
August 14, 2009
Seat
Left
Flight hours
387 total · 316 in this make and model · 343 as pilot in command

Weather

Conditions
Visual (VMC) · Day
Wind
10° at 3 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
50 °F, dew point 43 °F
Altimeter
29.97 inHg
Observed at
kavp, 20 nm away

Docket · 5

The files NTSB released with the investigation on November 6, 2009, on NTSB’s docket system: statements, records, photos and specialists’ reports. 2.1 MB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.